Hy gays, I made a project car (PUMA VOLKSWAGEN, a brazilian car) and in Blender it’s wonderful, too on 3D Builder, when I send to slicer, model looks very bad and I don’t know what’s 's happening.
Hey, @Guto_Lebsa we are not able to help you at all if you provide so little information.
screenshots of the problems + information of what steps you took + infos about the programs used + ideally the 3d file and so on…the more the better
always ask yourself could a person that has no previous information at all really understand the situation you are describing?
Have you done the standard checks in Blender?
In edit mode with all selected, check for doubles by pressing M > By Distance. Then press Shift-N to fix any flipped normals. Double check this by using the overlays window to turn on the Face Orientation Overlay to make sure all faces are correctly orientated.
Have you turned on the 3d print Add-on that comes with Blender? In Preferences > Add-ons, find Mesh: 3D-Print Toolbox and turn it on. Then in the 3D window side panel run the Add-on to check for problems.